[mythtv-users] Video encoding and ffmpeg
jtlarson at u.washington.edu
Tue Oct 12 16:03:29 UTC 2010
From: mythtv-users-bounces at mythtv.org [mailto:mythtv-users-bounces at mythtv.org] On Behalf Of Justin Bracken
Sent: Tuesday, October 12, 2010 7:09 AM
To: mythtv-users at mythtv.org
Subject: [mythtv-users] Video encoding and ffmpeg
Recently started messing with mythexport. Was kind of cool learning how to compile and all with me being a noob. I have been spending the weekend transcoding video to play on an iPhone 3GS. I'm running into some problems. One is that it seems I cannot encode with h264 and mp3 into a mp4 file or I believe an m4v file. <SNIP>
Any particular reason you want to use mp3? What errors do you get?
<SNIP> The rub now is that for some reason libfaac is not properly setting the bitrate and it seems like any player I choose assumes it's 128k instead of the correct value of 192k. This appears to cause a audio sync problem. Which took me a while to realize it could not be fixed with itsoffset.
I'm not sure how the audio bitrate could cause a sync problem, but setting the audio sample rate might. In ffmpeg 0.5.1, the sample rate is set with the '-ar' switch--e.g. -ar 44100 sets a sample rate of 44100 (standard CD sample rate) for the output.
If you need more assistance, run some tests and copy the output in your response.
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